Intermittent film movements having film registration



2 Sheets-Sheet 1 .nI/Enar" Eras-:Laye ZU. Jansan July 5, 1949. G. w. JoNsoN INTERMITTENT FILM MovMENTs HAVING FILM REGISTRATION Filed Jan., 30, 1948 July 5, 1949 G. w. JoNsoN 2,475,099

INTERMITTENT FILM MovEMENTs HAVING FILM REGISTRATION Filed Jan. 30, 1948 2 Sheets-Sheet 2 Patented July 5, 1949 UNI-'reo STATES fioFFicE INTERMITTENT. FILM MovnMEN'rsnAvmG FILM REGISTRATION Gustave W5 Jonson; Van Nuys; Galiflaassign'o to Mitchell .Camera Corporation; Glendalalif.; acerporation-of Delaware Application". January. 30, 1948,{Siall`la '5",293

(Cl. 88--18i4l 3 Claims. 1

-Th-is`=inver1tion relatesgenerally to kinetograph movements of l the `tyne having an intermittent film-moving `mechanism` anda cooperating film registering mechanism which=locks the film in accurately registeredlposition Whileit is-not being moved. The pointsat Whichthe lmmoving and thefilm registering vmechanisms respectively engage twfilm perforations are ordinarily separated, andthat separation' must be properly related to the spacing-of thelm-perfo1`ations- Since the latter-spacingvaries somewhat with such'factors as 'moisture 4.content of the nlm, it is desirable; to provide. acompensating ladjustment in the movementibylwhich the relative positions of the tvo film engaging devices can be varied to suit-various-nlm conditions.

.More particularly, the-invention concerns an adjustment mechanism ofthe above type which'is especially Well adapted for use With a claw type of vi'llm moving mechanism in which the claw carrying. .arm andthe actuating mechanism which controlslits motionarel entirely Asupported by a drive Ashaft and' by a` pivot-mounted on a pivot axisparallelto the drive fshaft, for example in themanner to be described. Insuch mechanisms, thewparallel drive shaft axis and pivot axis togetherfdene a plane .Whichiishere'ref erred toas the axial plane of the intermittentmechanism.

An .important object of the present'invention is to provide in such a movement k-meansfor 4accurately adjusting the spacing'betw-een the :nlm engaging positions of the-lmimoving and thelm registering mechanisms, while maintaining Athe pattern of ymotionof each individual mechanism and the .relative .timing of the two mechanisms substantially constant.

Further .objectsof the invention are to provide an adjustment of-theftype described which is'rel'atively simple and economical to construct; which can be accurately Aand conveniently adjusted While .the machine is in operation; which can Vbe rnrly locked in its adjusted Apositionyand which, Whenlocked, ,provides a satisfactorily rigid support for the moving parts of the mechanism.

These and other objects and advantages are attained, according to the present invention, by mounting the intermittent mechanism on the frame in such a Way that it is lad-justably movable with respect to the frame to vary the position along thefilm chute at which it engages the film.

W'ithytl-ieV preferrediorm of `c'lavv mechanism described above, such adjustability of the mechanism is preferably obtained by mounting theguide pivot so-that its pivot axis is movable transversely of the above denned axial plane `of the mech- '2 anism. `Ii`pai'till{2'1"15'7; by limiting thepivot aldjustability"to'notion-Aabout the drive shaft asian axis,- "tle entire intermittent mechanism is' made inL effect 't'ofswing-1 "abti the shaft axis, andi this tern alongl the lfin chiite toward orv away from th'eiilmf1registeringmechanism` without* disturb'- ing the stroke patter-nvitsel.

" The :fexact nature 'of the invention, l together f withr' further obj eiztsV arid!- advantages' thereof, 'v'vill be `rr'ioreill'lly understoodfroni the following illustrative description off'a pref erred manner of' carryingfit into effect-'in connection with a typical formv of 'fklnetdgraph-movment. This description, Whichlisnotiin'tendedto limit' thef broader scope of my? invention, is ltoiberead in conjunction withthe"accompanyingfdravvin'gs, of which:

:Figs 1Ji's1a' side 'elevation ofi akin'tograph 'movemerit "embodying: the invention;

' sla -vetical-sectiontaken as indicated e 3-23 inFigjl;

"Fig 'iis a `fragm'e'ntary Sectiontaken as lindicatedfbythe'f'linefd-fl in Fig. 1;

'-Fig."!7 isa di'agrarnmati'cllayout of the 'movement, 'illustrating Ithe `paths of motion oi certain points in the mechanism.

Itlwillbelco'rivenient'to describe lrst the structure o' 'the' illust'rated typical lm movement without reference 'to `the vf'embodiment therein 'of the ypresent vinvention.

ln' the drawings the numeral flil designates a vertical `aperture fp'late having an exposure apertufrewliL-alnd numeral I2 designates a vertical frame 1platef-arra'nged at r-ight ang-les to and extending rearwardly from anie'dge-of'plate I0, said plates .Iland lll2 being adapted to be mounted in anysuitable manner-'inthemotion picture machine; 'not shown. `"spaced Vre"'a`rw`a'ri:lly from a'perturePpvlate -i Band eiot'ending at `right angles from plate |2 is a guidefplat'e I3, lbetween which and the aperture plate'is the'guidevvayor nlm chute I4 for the lmfF, which is shown in the lower 'portion-lof yFi`g.f3, but is omitted from the other dwellfthats, alternately Withth'e periods 0f pull down, by the iilm holding and registering means, indicated generally at I6, which registers successive iilm frames I1 with exposure aperture II.

Intermittent movement I engages film perforations I8 by means of suitable claw pins 20 which are mounted on a cross arm 2| on the forward end of claw arm 22. The rearward end of claw arm 22 is pivoted at 23 to driving arm 30, and the intermediate portion of the claw arm is guided by the claw arm cam, preferably a circular eccentric, 25, which engages the sides of longitudinal guide slot 26. Circular cam 25 is eccentrically mounted at the outer end of main driving shaft 28, which is journaled in a bearing 29 in sleeve 12, rigidly mounted on a frame plate I2 and carrying nut 13.

Driving arm 30 is provided forwardly of pivot 23 with a strap portion which embraces driving arm cam (circular eccentric) 3|. Cam 3| is mounted on driving shaft 28 inwardly of cam 25,

and in the present embodiment is 180 out ofV phase with the latter cam and has relatively small eccentricity. The forward end portion of driving arm 30 is in the form of a cylindrical slide rod 32 which slides in and is guided by a pivoted guide block 35. The latter is pivoted by means of trunnion 36 in bushing 31, which is mounted on frame plate I2 by means to be described.

In operation, rotation of driving shaft 28 (clockwise as seen in Figs. 1, 5 and 7) causes driving arm 30 to oscillate about the pivot axis of trunnion 36 and to reciprocate with respect to pivoted guide block 35. Pivot 23 is thus moved through a generally elliptical path, as indicated schematically in Fig. '1. That motion is imparted by pivot 23 to the rearward end of claw arm 22, and produces, in combination with the action of claw arm cam 25, a motion of claw pins along a stroke pattern such as that indicated in Fig. '7. The lower portion Ida of Iilm chute I 4 is preferably curved rearwardly as indicated in Figs. 1, 5 and 7, following roughly a circular arc about the axis of drive shaft 28, thus conforrning generally to the overall shape of the stroke pattern of claw pins 20. At the upper end 93 of the claw stroke, pins 20 engage film perforations, then move downward, drawing the film through film chute I4, and are retracted from the lm at the lower end 9I of the stroke. The length of each stroke is as nearly as may be equal to the interval between successive film frames, so that von the following stroke the claw pins cleanly enter another set of iilm perforations.

The intermittent mechanism here described is typical of movements in which motion is transmitted to a claw arm from a cam or the like on a driving shaft, and in which the claw arm and its actuating mechanism are entirely supported on the driving shaft and on a pivot. Movements of this general type are well known in which a single rather than a double cam is used, and the cam or cams may be of various types, including, for example, a cam working in a box. The pivot upon which the intermittent mechanism is partly supported may be fixed with relation to a member of that mechanism and be mounted for reciprocating motion relative to the machine frame, rather than the opposite relationship as in the present modification, in which pivot trunnion 35 has a relatively xed pivot axis and is' slidingly related to driving arm 30 of the intermittent mechanism. Furthermore, the pivot need not be located between the driving shaft and the film chute, but is frequently mounted, for example, on the opposite side of the driving shaft from the film chute. These and other modifications are well known in intermittent movements of the general type defined above, typical examples of such modifications being found, for example in Patent No. 936,031, issued on October 5, 1909, to J. J. Pink and in Patent No. 1,850,411 issued to G. A. Mitchell on March 22, 1932.

Film holding and registering means I6 of the present preferred embodiment engages the lm by means of pilot pins 40 which are mounted on the offset cross arm 4 I. Cross arm 4I is supported and guided for reciprocating motion toward and away from film chute I4 by two rods 42, mounted in slide bearings in bracket 43, and by an interu mediate rod 45, having a slide bearing in bracket 4E. Brackets 43 and 46 are mounted on and project from frame plate I2 as shown in Figs. 1, 3 and 5. Reciprocating motion in timed relation to the motion of intermittent mechanism I5 is imparted to cross arm 4I through intermediate rod 45 by a linkage which comprises three principal members. These are upper link 50, bifurcated at its forward end and pivoted at 5I to rod 45 (Fig. 3); lower link 53, pivoted at its rearward end at 54 to driving arm 30 of the intermittent mechanism at a point spaced rearwardly of and somewhat below pivot 23 (Figs. 2 and 5); and lever 56, pivotally connected at its ends respectively to the rearward end of link 50 at 52 and to the forward end of link 53 at 55, and pivotally mounted near its center at 51 on bracket 53. Bracket 58 is adjustably supported on frame plate I 2 as will be described, but is normally rigidly held in the position shown, for example, in Fig. 1.

The linkage 5i), 56, 53 transmits the reciprocating motion of driving arm 30 of intermittent mechanism I5 to cross arm 4I and pilot pins 40 of the registering mechanism, centrally pivoted lever 53 serving to invert the phase of the motion of one mechanism relative to that of the other. Thus pilot pins 40 are moved into film engagement as claw pins 20 are withdrawn, holding the film in registered position throughout the period of lm dwell. Then, as claw pins 20 move forward to re-engage the lm, pilot pins 40 are withdrawn, releasing the i'llm for the succeeding pull down stroke.

As will be seen from Fig. '7, pivot 54 at the rearward end of driving arm 30 (from which registering mechanism I1 is actuated) describes a path which includes a rearward portion which is approximately circular and a forward noncircular portion. (In Fig. '7 the paths of the several parts are indicated by the same numerals, encircled, as have been applied to the parts.) Pivot 55 is located approximately at the center of curvature of the circular portion of that path. Accordingly, while pivot 54 is describing the rear- Ward portion of its path, that is, while claw pins 29 are withdrawn from the film, lower link 53 tends merely to swing around pivot 55 as a center, imparting substantially no motion to registering mechanism I6. This has the advantage that pilot pins 40, after engaging the film, remain substantially stationary in full lm engagement during the greater part of the period of film dwell. In other words, particularly during the period of dwell, the registering mechanism is actuated primarily by the reciprocating motion of the intermittent mechanism, and is relatively independent of the oscillating motion of that mechanism.

In order to permit claw pins 20 and pilot pins 40 to be simultaneously withdrawn from iilm chute I4 and thus facilitate threading of the lm,

pivot 51, which carries linkagelever 56, is movably mounted on frame plate I2, as byfmeans of lever BILFig. 1. As illustrated, lever Ellis pivoted at a `point intermediate its length by screw stud 6I to frame plate I2, andcarries bracket58 for pivot 51 at its upper end. The lower portion of lever 6l] carries-a locking pin. 62 which-enters bore 63- in plate I2 to lock the lever in its normal operating position. By means of handle Bdlpin 62- can be withdrawn from hole 63r against the force of spring 65 to release lever 60 for swinging motion about itspivot 6 I vin a clockwise direction as seen in Figs. 1 and5. That motion moves pivot 51 rearward, swinginglinkage lever Sgenerally aboutits lower pivot 55 in a clockwise direction. and withdrawing pilot pins 40 froml lm engagement in all positions of intermittent mechanism I5.

The aboveV described mechanism is a typical example of film movements whichmay embody the'present invention. Certain `features of the movement itself, as thus far described, are discussed in more. detail and are claimed in Patent No. 11,930,723, issued to 'George A.. Mitchell on October 27, 1933.

A` preferred illustrative manner in which the present invention can be embodied in this particular type of movementwill now be described. Asupport member .19in the --form of a plate with a stra-p `por-tion 1I .is-mounted with the strap portion embracing the mounting sleeve 12 -of driving shaft bearing 29, Yand is confined between frame plate I2 and bearing retaining nut 13, carried by the sleeve. Plate isvthus rotatable about the axis of driving shaft-28, but is restrained against other motion by sliding contact of its outer and inner faces respectively 4with retaining nut 13 and `irameplate I2. Plate 19v has a circular edge portion 15, which generally follows the lower curved `portion 14a of film chute I4, and whichl fits slidingly between frame plate. I2 and the edge o-f guide plate I3, cut away to receive it as indicated at 16.

Guide block 35 of the intermittent movement ispivotally mounted on support -plate 10, rather than directly on framev plate. I2. In the preferred form illustrated, journal bushing 31, in which pivot trunnion` 36 of guide block 35 is pivotally mounted., isfixed in bracket 18, screwed tothe inner vface oi supportplate 1B, and projects outward through an opening in that plate. A clearance opening 19 is cutinirame `plate I2vto receive bracket 18y allowing adequate clearance fortherelatively-slight.motionof the latter which is required.

Locking. -means are provided by which support plate 1li can be clamped against frame plate i2 and locked against swinging Iabout the axis of drive shaft `28.. `As illustrated,a clamping screw 8U passes through a slotted or oversize `opening BI in plate 1Il and is threaded into frame plate I2 (Fig. 6). ponloosening of screw; the rotationalposition of support plate 10 (and hence of pivotf36). is accurately-adjustable byvadjustment means, illustratively shown Yas comprising eccentric pin 82. The latter `has a trunnion 83- journaled-inframe plate I2 (Fig. 6l, and-an eccentric portion 4'lI which rotatively carries a slider block 85. Block 85 fits slidingly in a groove 8E, cut in plate 1n radially with respect to shaft 2B. Groove 86 has :lianges 81 at the outer face of plate 10, which overlap and retain block 85, thus retaining also vpin B2 by contact of the inner face of block 85 with pin flange 8B, which is intermediate the shaft and eccentric portions 6 ofethefpin. Theouter-endotpin 82- carries a tool fitting, such as slot 891adapted toreceive ascrew driver, by which the pin vcan be accurately rotated about theaxis of its trunnion 83.

4Such rotation displaces-slide block 85, due to depends upon the maximum anticipated variationin. film dimensions,.which is roughly 1%, anduponathe distance from pilot pins 40 to the lower 4endvof the claw stroke, indicated at 9| in Fig. 7. Even if, as is normally the case, claw pins 2!)v fit lm p erforatioris` I8 with an appreciahlevertical clearance, -thelm is brought by each intermittent movement to a position which is precisely.` defined with relation to point 9|. Thatposition mustbe such as. to bring a set of, i`1lm.perforations` directly opposite pilot pins Ml,-whichordinarily fit the perforations with virtually no vertical clearance. In practice a sufficient range of adjustment isobtained if the entriity 0f Din-2 .82 is approximately 0.020".

In the broader aspects of the present invention it may not be objectionable to move the pivot axis non-concentrically with respect to the axis ofdriving shaft 28, even though such motion affects somewhat vthe stroke pattern. Thus pivot ltrunnion 316 may be mounted in any. manner which, permits adjustable. movement generally transversely of driving arm 3D', or, more exactly, transversely ofythe common plane defined by the --fpivotfaxis :andi-the axis of drive shaft 28.

lAn v4advantageof the present preferred embodiment is that, 'wh-ile theorientation Within the machine-frame ofi theinterm-ittent mechanism I5 fas a wholefis adjustably varied, the arrangement 'of -tlrreparts within the intermittent mech- 'anism itself isnot affected. In particular, those internal characteristics of the 'mechanism which determine the stroke patternofclaw pins 2l] remain constant. LThe separation `of the parallel axes V.of driveshaft -28 and guide block pivot 2t isone of those characteristics, and Yis seen to remainstrictly constant, since only rotational motion Labout shaft 2'8- is linvolved inthe 4adj ustment The-result can be clearly visualized from Fig. 7, `in lwhich the effect `of th'e adjustment is 1to rotatefthe entire stroke pattern lof claw Aarm 22-'and1idrivin-g. arm 30 about thefcommon axis of eccentricicams25:ande3i taxis of shaft 28). The path `of `pizrclaws f2.0.; (at'the left in Fig. '1) is thus' moved; bodily and-.without `distortion of the 'path itseliifalong. the curved portion Ma of iilni chute -I-4. `Since the ifor'myof chute portion 'Ma approximates af'circulararcf about Vshaft 23, the points 90, 9| along the path of the pin claws at which they respectively engage and disengage the film remain substantially unaltered by the adjustment. Such slight motion of points and 9| along the path 2U as may result, if chute portion Ma is not strictly circular, can cause only a second order variation in the effective length of the pull-down stroke, since at points 7 90 and 9| the path of claws 20 is approximately normal to the film chute.

As has been pointed out, lm holding and registering mechanism I'I is actuated primarily by the reciprocating motion of the intermittent mechanism and only secondarily by its oscillating motion. Since the reciprocating motion is radial with respect to shaft 28, the rotational adjustment of pivot 36 about shaft 28 produces no component of displacement parallel to that reciprocating motion. Thus the adjustment can affect the action and the relative timing of registering mechanism I6 only to the relatively slight extent that that mechanism is actuated by the oscillatory motion of the intermittent.

The present detailed embodiment is especially adapted for use in a background projection machine, in which the lm aperture I I must transmit a particularly intense light beam and is therefore subjected to unusually high temperatures. In such a machine the intermittent mechanism I is preferably spaced especially far below nlm aperture il, leading to a wider separation between claw pins 20 and pilot pins il than, for

example, in mechanisms designed for cameras. For this reason, and also because the condition of iilm to be projected cannot in practice be controlled as closely as that of raw lm, the embodiment of the present invention in a machine of this type offers particularly great practical advantages. However, the invention can be used with cameras as well as with projection machines, and it is not intended that the present illustrative embodiment be interpreted as limiting the :cope of the invention, which is dened by the following claims.

1 claim:

l. En. a iilm movement having a frame, a lm guideway mounted on the frame, a rotatable drive shaft journaled in the frame, lm moving means of the claw type adapted to engage the film intermittently at a definite longitudinal position of the guideway, said lm moving means being entirely supported by the drive shaft and by a pivot mounted on a pivot axis parallel to the axis of the drive shaft, and film registering means operatively connected to said lm moving means for actuation in timed relation therewith and adapted to engage the film at a fixed position longitudinally spaced along the guideway from 'the iirst said position; the improvement which comprises a support member mounted on the frame and rotationally adjustable about the axis of the drive shaft, the said supporting pivot being mounted on the support member, whereby the pivot axis of the supporting pivot is adjustable along a circular are about the axis of the drive shaft to vary the longitudinal spacing between ,ie film registering means and the position of .film engagement of the lm moving means while maintaining other operating characteristics of the film movement substantially constant.

2. In a lm movement having a frame, a rotatable drive shaft journaled in the frame, a lm guideway supported on the frame and having a curved section approximating a circular arc about the axis of the drive shaft, lm moving means of the claw type entirely supported by the drive shaft and by a pivot mounted on an axis parallel to the axis of the drive shaft, the film moving means incluidng a claw arm carrying a lm engaging claw and means for moving the claw transversely of the lm guideway into and out of lm engagement and longitudinally of the guideway along a denite portion of its length which lies substantially within the said curved section, and film registering means adapted to lockingly engage the lm at a xed position longitudinally spaced along the guideway from the said portion of its length, said film registering means being operatively connected to the lm moving means for actuation in timed relation therewith by virtue primarily of the said transverse motion of the claw; settable means for adjustably varying the position along the guideway of that portion of the guideway within which the claw motion takes place to vary the distance between that position and the fixed position of i'llm engagement o f the film registering means while maintaining other characteristics of the lm movement substantially constant, said settable means comprising movable support member upon which the said supporting pivot is mounted, said support member being mounted on the frame for rotational motion through at least a small angle about the axis of the drive shaft, means for adjustably moving said support member, and means for reeasably locking said support member with respect to the frame.

3. In a film movement of the type which includes a frame, a rotatable drive shaft journaled on the frame, a nlm guideway mounted on the frame and having a portion which is curved approximately concentrically about the drive shaft, and lm moving means of the claw type adapted to engage the film intermittently at a definite longitudinal portion of the guideway within the said curved portion thereof, said film moving means being entirely supported by the drive shaft and by a pivot mounted on a pivot axis parallel to the axis of the drive shaft; the improvement which comprises a support member mounted on the frame and rotationally adjustable about the axis of the drive shaft, the said pivot being mounted on the support member, whereby the pivot axis is bodily shiftable about the shaft axis to vary the position'along the guideway of the point of lm engagement of the lm moving means, while maintaining other operating characteristics of the film movement substantially constant.

GUSTAVE W. J ON SON.

REFERENCES CITED The following referenlces are of record in the 

